Full stack to help satisfy curiosity
Curiostack only has a dependency on Java. However, IntelliJ is highly recommended for development. The free community edition is sufficient for Java development, while the pro edition may provide a more integrated IDE for both server and client development. Many users will choose to use IntelliJ community edition for server side development and Atom or Visual Studio Code for client side.
To work on IntelliJ, clone the repository and in a command line, run
$ ./gradlew idea
to generate initial IntelliJ configuration. Then open up the folder in IntelliJ and say yes when it asks you to link the project.
All code-style, license, etc setup will be done automatically, and you're ready to code.